Improvement in vehicle-springs



w/EvANs. IVehicle-Springs. l

5 510.155,50). Patented sept.29,1,874.

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UNITED STATES PATENT OFFICE.

WILLIAM EVANS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO BENEZET &COMPANY, OF SAME PLAGE.

IMPROVEMENT IN VEHICLE-SPRINGS.

Specification forming part of Letters Patent N0. 155,509, datedSeptember 29, 1874 application filed April 27,1874.

To all whom it may concern.'-

Be it known that I, WILLIAM EVANS, of the city of Philadelphia,Pennsylvania, have invented certain Improvements in Springs forVehicles, of which the following is a specification:

My invention relates to the construction of carriage-springs of thecharacter illustrated in the perspective view, Fig. l, of theaccompanying drawing, where two springs, A A', are combined with a thirdtransverse spring, B, the fulcrum of each of the said springs A A beingnearer to one end of the same than to the other; and the object of myinvention is to equalize the elasticity of the long and short portionsof the spring. Compound springs of this class are in general use foreXpress-wag `ons and other heavy vehicles, the springs A A resting uponand being secured to the axle, while the extremities of the long arms ofthe said springs A A', and the central portion of the transverse springB, are secured to the body'of the vehicle, or to a frame pivoted to thesaid body.

On reference to the side View, Fig. 2, of the spring A it will be seenthat it is composed of three layers, a, b, and c, the iirst being turnedat the opposite end so as to form the usual eyes e e. The three layersare conined at the usual point between the opposite ends by a strap, D,and clip-plates j' and g, as best observed in the transverse section,Fig. 3, on the line l 2, the strap and clip plates taking the place ofthe usual center bolt, which weakens the spring, and is apt to becomecut or broken off. Where the strap and clip plates bind the layerstogether, a projection or teat on one its into a recess in the other, sothat all the* layers are maintained in the same relative 1ongitudinalposition. formed with corresponding teats and recesses adapted to thoseof the layers of the spring, while the strap D is adapted to a groove inthe upper clip-plate, f, and the lower clip-plate, g, has shoulders atits opposite sides, which overlap the lower layer of the spring, thisalso tending to maintain the several parts in their proper relativepositions. In the longest portion of the spring y from the fulcrum a',the layer a has a rib adapted to a groove in the layer b, the latterhaving a similar rib adapted to a groove in the layer o, which has alsoa rib on its under side, as best observed in the transverse section,Fig. 4, on the line 3 4. In the short portion of the spring y from thefulcrum a', the layers are made without ribs and grooves. As usuallyconstructed, the long portion of a spring of this class is necessarilymore elastic than the short portion, but by making the longer portionwith ribs in the manner described, its rigidity may be increased tocoliform with that of the short portion. In other words, the elasticityof both portions of the spring is equalized by the presence of ribs inthe long portion.

I claim as my invention- 'Ihe spring A, consisting of the combination oflayers a b c, conined at w to form long and short arms y y', and havingribs and grooves in the long arm, as set forth.

In testimony whereof, I have signed my naine to this specification inthe presence of two subscribing witnesses.

WILLIAM EvANs.

Witnesses:

WM. A. STEEL, HUBERT HowsoN.

The clip-plates are also

